When I was a very little kid (3-5, let's say), I overheard my mom talking on the phone about how a nice older lady named Kay had gotten bumped in a fender-bender. At some point later (in mixed company, I'm guessing), I loudly announced, "KAY GOT BOMBED!" (that is, drunk). For years this poor innocent lady was then known as "Kay-got-bombed."
I mention this because on Saturday, as I was giving Finn his morning milk on my lap, his overnight diaper leaked through onto my shorts. Getting up and seeing the spot, he said, "Dad-O peed!!" I protested that noooo Dad-O didn't pee, but my & Margot's laughter sealed the deal: Every time he's repeat his claim, we'd laugh, and now it's become established fact that, yep, Dad-O peed & had to change into the space monkey shorts.
It may take a while, but what goes around does, in fact, eventually come around.